Antenna and apparatus comprising this antenna

ABSTRACT

The present invention provides an antenna in which, on a dielectric substrate  1  having a back face on which a grounding conductor plate  14  is disposed, a plurality of conductor elements  12  are arranged in a matrix of rows and columns. Each of the dielectric elements  12  has a size which cannot function as an antenna. Above the conductor elements  12,  a connecting element  13  overlapping two adjacent conductor elements  12  is disposed. Among the connecting elements  13,  some cause the conductor elements  12  on both sides to be in a conductive condition, and others cause the conductor elements  12  on both sides to be in a non-conductive condition. The switching between the conductive and non-conductive conditions between the conductor elements  12  can be dynamically performed by a switching element.

TECHNICAL FIELD

The present invention relates to an antenna used for receiving andtransmitting electromagnetic waves such as micro waves and millimeterwaves, and particularly to an antenna most suitable for a portableinformation terminal utilizing radio transmission and for equipment fornetwork (so-called wireless LAN) in a personal computer. The preventinvention also relates to various types of apparatuses provided with theantenna.

BACKGROUND ART

In the fields of television, radio, and the like, various types ofantennas are previously developed for receiving or transmittingelectromagnetic waves of picture and image signals. The known antennasinclude an aperture antenna such as a parabolic antenna and a reflectivemirror antenna, a linear antenna such as a dipole antenna and a patchantenna, and an array antenna such as a planer antenna and a slotantenna, for example.

For such antennas, a lot of improvements are made mainly for thepurposes of improving the factors of directivity, gain, impedance, andthe like. The form (topology) and the location of an antenna aredesigned and determined so that the directivity, gain and impedance areoptimized, depending on the frequency of radio wave to betransmitted/received, and the direction from which the radio wave isreceived.

Recently, in accordance with the developments of portable informationterminals utilizing radio transmission and equipment for network(so-called wireless LAN) in personal computers, flexibility is requiredfor the functions of antennas.

Especially in the case where a mobile instrument such as a portableinformation terminal is used while it is being moved, it may bedifficult to carry the radio wave depending on the location, and thepower of transmission/reception signals may be weak. Thus, the S/N ratioof the signals may disadvantageously be reduced. In connection with theincrease in frequency of electromagnetic waves, a probability that theelectromagnetic waves are reflected from an obstruction, thereby causinga so-called multi-pass is increased, and the accuracy of radiocommunication is degraded.

For the above-described reasons, we require an antenna which canmaintain good transmission/receiving characteristics by adapting to anypossible change in communication conditions. As the frequency of asignal becomes higher, the directivity of radio wave becomes stronger.Thus, in the case where a number of wireless terminals exist in acommunication range, an antenna is required to have a function ofrealizing communication through a path (an optimum radio path) foreffectively communicating with a wireless terminal to be connected.

However, in a conventional antenna, the form of the antenna is fixed, sothat the characteristics of the antenna is substantially uniformlydetermined depending on the predetermined form. Therefore, it isdifficult to maintain good transmission/receiving characteristics byadapting to the change in communication conditions. Especially in thecase where the frequency of the electromagnetic waves to be handled, andthe incident direction of electromagnetic waves are changed, it isdifficult to change the antenna characteristics by following the changedconditions.

A main object of the present invention is to provide an antenna capableof dynamically changing the form of an antenna element so as to optimizethe parameters of a directivity characteristic, a gain characteristic,an impedance characteristic, and the like of the antenna.

Another object of the present invention is to provide an apparatusprovided with such an antenna.

Still another object of the present invention is to provide a producingmethod and a designing method of an antenna which can determine anoptimum form in given conditions by dynamically changing the form of anantenna element.

DISCLOSURE OF INVENTION

The antenna of the present invention includes: an array of a pluralityof conductor elements which are mutually separated, and each of whichdoes not independently function as an antenna; and coupling means forelectro-magnetically coupling at least two conductor elements selectedfrom the plurality of conductor elements, thereby causing the pluralityof coupled conductor elements to function as one antenna element.

In a preferred embodiment, the antenna further includes a dielectriclayer for supporting the plurality of conductor elements, wherein thecoupling means includes conducting means for electrically connecting theplurality of selected conductor elements.

In a preferred embodiment, the array of the conductor elements includesa matrix portion in which the plurality of conductor elements arearranged in a matrix of rows and columns.

In a preferred embodiment, the matrix portion of the array isconstituted by conductor elements having substantially the same shape.

In a preferred embodiment, the matrix portion of the array isconstituted by conductor elements having substantially the same size.

In a preferred embodiment, each of the plurality of conductor elementshas a size smaller than a wavelength of radio wave to be transmittedand/or received.

In a preferred embodiment, the conducting means includes a group ofconductor pieces overlapping at least two adjacent conductor elements,and the conductor pieces are arranged for electrically connecting theselected conductor elements.

In a preferred embodiment, the antenna further includes a dielectricfilm interposed between the respective conductor elements and therespective conductor pieces.

In a preferred embodiment, the conducting means includes a plurality ofswitching elements for switching electrically conducting/non-conductingconditions between two conductor elements.

In a preferred embodiment, the plurality of switching elements arearranged in a matrix of rows and columns.

In a preferred embodiment, the antenna further includes a wiring layerfor connecting a circuit for driving the plurality of switching elementsto the plurality of switching elements.

In a preferred embodiment, the switching elements are transistors.

In a preferred embodiment, the switching element includes a conductorpiece which is movably supported, and an actuator for moving theconductor element, and the actuator can reciprocate the conductor piecebetween a first position in which a plurality of adjacent conductorelements are electrically connected by the conductor piece and a secondposition in which a plurality of adjacent conductor elements are notelectrically connected.

In a preferred embodiment, the dielectric layer has a first main face onwhich the array of conductor elements is disposed, and a second mainface opposite to the first main face, and a grounding conductor isformed on the side of the second main face.

In a preferred embodiment, part of a plurality of conductor elementsselected from the plurality of conductor elements function as agrounding conductor.

In a preferred embodiment, the dielectric layer, the conductor elements,and the conducting means are laminated.

In a preferred embodiment, the conducting means is provided in a movablemanner, and the antenna further includes a moving mechanism for movingthe conducting means between a conducting position in which the at leasttwo conductor elements are made to mutually and effectively conduct, anda non-conducting position other than the conducting position.

In a preferred embodiment, the coupling means includes a conductorlayer, and a plurality of dielectric elements disposed between theconductor layer and the respective conductor elements, and the selectedconductor elements are more strongly capacitive-coupled to the conductorlayer than the conductor elements which are not selected.

In a preferred embodiment, the array of the conductor elements includesa matrix portion in which the plurality of conductor elements arearranged in a matrix of rows and columns.

In a preferred embodiment, the matrix portion of the array isconstituted by conductor elements having substantially the same shape.

In a preferred embodiment, the matrix portion of the array isconstituted by conductor elements having substantially the same size.

In a preferred embodiment, each of the plurality of conductor elementshas a size smaller than a wavelength of radio wave to be transmittedand/or received.

In a preferred embodiment, the dielectric elements positioned betweenthe selected conductor elements and the conductor layer are thinner thanthe dielectric elements positioned between the conductor elements whichare not selected and the conductor layer.

In a preferred embodiment, a specific inductive capacity of thedielectric elements positioned between the selected conductor elementsand the conductor layer is larger than a specific inductive capacity ofthe dielectric elements positioned between the conductor elements whichare not selected and the conductor layer.

In a preferred embodiment, the antenna further includes an actuator formoving the conductor elements so as to change a distance between each ofthe conductor elements and the dielectric layer.

In a preferred embodiment, the dielectric elements and the conductorelements are layered a plurality of times.

The antenna module of the present invention includes: one of theabove-described antennas; and a driving circuit for generating a signalfor driving the plurality of switching elements.

The apparatus of the present invention includes: one of theabove-described antennas; a driving circuit for generating a signal fordriving the plurality of switching elements; and control means forcontrolling the operation of the driving circuit, based on a signalreceived and/or transmitted by the antenna.

In a preferred embodiment, the apparatus further includes evaluatingmeans for evaluating directivity, gain, and/or impedance of the antenna,based on the signal, wherein conductor elements to be electricallyconnected are dynamically selected from the plurality of conductorelements, based on the evaluated result.

In a preferred embodiment, the evaluating means evaluates thedirectivity, gain, and/or impedance of the antenna for each of aplurality of combinations of conductor elements which are electricallyand mutually connected by the switching elements.

In a preferred embodiment, the apparatus further includes: a memory forstoring the evaluated results for the plurality of combinations of theconductor elements; and a form designing section (topology searchsection) for selecting conductor elements to be electrically andmutually connected by the switching elements and for controlling theoperation of the driving circuit, based on the evaluated results storedin the memory.

The system of the present invention is a system including a plurality ofabove-described apparatuses, wherein communications are performedbetween the plurality of apparatuses by radio waves via antennas of therespective apparatuses, and connection patterns of the plurality ofconductor elements are dynamically changed for defining forms of theantennas of the respective apparatuses.

The production method of the present invention is a production method ofan apparatus provided with an antenna includes: a step of forming anarray of a plurality of conductor elements used for forming a conductorpattern defining a form of the antenna, the plurality of conductorelements being mutually separated; and a step of forming conductingmeans for selectively and mutually connecting some of the plurality ofconductor elements, thereby determining the conductor pattern.

The designing method of the present invention is a form designing method(topology searching method) of an antenna in an apparatus provided withthe antenna including a step (a) of forming an array of a plurality ofconductor elements used for forming a conductor pattern defining a formof the antenna, the plurality of conductor elements being mutuallyseparated; a step (b) of selecting desired conductor elements from theplurality of conductor elements, and for electrically and mutuallyconnecting the selected conductor elements; and a step (c) oftransmitting and/or receiving radio waves by using the conductorelements which are electrically and mutually connected, and forevaluating directivity, gain, and/or impedance of the antenna, whereinthe steps (b) and (c) are repeatedly performed for differentcombinations of the conductor elements to be selected.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(a) is a plan view showing an exemplary configuration of aconventional planer antenna of current control type, and FIG. 1(b) is aplan view showing an exemplary configuration of a planer antenna ofcurrent control type according to the present invention.

FIG. 2(a) is a plan view showing an exemplary configuration of aconventional planer antenna of magnetic current control type, and FIG.2(b) is a plan view showing an exemplary configuration of a planerantenna of magnetic current control type according to the presentinvention.

FIG. 3(a) is a perspective view showing an arrangement of conductorelements 12 in a first embodiment of a planer antenna according to thepresent invention, and FIG. 3(b) is a perspective view showing theantenna on which connecting elements 13 are disposed.

FIGS. 4(a) to 4(c) are plan views showing arrays of conductor elements12 having various planer shapes in the first embodiment of the presentinvention, respectively.

FIGS. 5(a) to 5(c) are plan views showing other exemplary arrangementsof the array of conductor elements 12 in the first embodiment of thepresent invention.

FIGS. 6(a) to 6(c) are plan views showing still other exemplaryarrangements of the array of conductor elements 12 in the firstembodiment of the present invention.

FIG. 7 is a sectional view showing a first example of connectingelements in the first embodiment.

FIG. 8 is a sectional view showing a second example of connectingelements in the first embodiment.

FIG. 9 is a sectional view showing a third example of connectingelements in the first embodiment.

FIG. 10 is a sectional view showing a second embodiment of the antennaaccording to the present invention.

FIG. 11 is a sectional view showing a current flowing in the antenna ofFIG. 10.

FIG. 12(a) is a perspective view showing an appearance configuration ofa third embodiment of the antenna according to the present invention,and FIG. 12(b) is a perspective view showing the antenna in a conditionwhere a dielectric substrate and conductor elements are removed.

FIGS. 13(a) and 13(b) are sectional views showing a first example ofconducting means in the third embodiment of the antenna according to thepresent invention, respectively.

FIGS. 14(a) and 14(b) are sectional views showing a second example ofconducting means in the third embodiment of the antenna according to thepresent invention, respectively.

FIGS. 15(a) and 15(b) are sectional views showing a third example ofconducting means in the third embodiment of the antenna according to thepresent invention, respectively.

FIG. 16 is a perspective view showing an appearance configuration of afourth embodiment of the antenna according to the present invention.

FIG. 17 is a perspective view showing a configuration of a fifthembodiment of the antenna according to the present invention.

FIG. 18 is a perspective view showing an appearance configuration of thefifth embodiment of the antenna according to the present invention.

FIG. 19(a) is a sectional view of a planer antenna in which three firstdielectric elements exist under three conductor elements, and FIG. 19(b)is a plan view thereof.

FIG. 20(a) is a sectional view of an antenna in which first dielectricelements having a larger area exist under conductor elements on bothends among three conductor elements,-and a second dielectric elementhaving a smaller area exists under the center conductor element 12, andFIG. 20(b) is a plan view thereof.

FIG. 21(a) is a sectional view of a planer antenna in which three firstdielectric elements exist under three conductor elements, and FIG. 21(b)is a plan view thereof.

FIG. 22(a) is a sectional view of an antenna in which first dielectricelements having higher dielectric constant ε 1 exist under conductorelements on both ends, and a second dielectric element having lowerspecific dielectric constant ε 2 exists under a center conductorelement, and FIG. 22(b) is a plan view thereof.

FIG. 23(a) is a sectional view of a planer antenna in which three firstdielectric elements exist under three conductor elements, and FIG. 23(b)is a plan view thereof.

FIG. 24(a) is a sectional view of an antenna in which first dielectricelements having higher averaged specific inductive capacity exist underconductor elements on both ends, and a second dielectric element havinglower averaged specific inductive capacity exists under a centerconductor element, and FIG. 24(b) is a plan view thereof.

FIG. 25(a) is a sectional view of a planer antenna in which threeconductor elements are in contact with dielectric elements,respectively, and FIG. 25(b) is a plan view thereof.

FIG. 26(a) is a sectional view of an antenna in which conductor elementson both ends are in contact with dielectric elements, but a centerconductor element center is separated from a dielectric element, andFIG. 26(b) is a plan view thereof.

FIG. 27 is a perspective view showing a horn antenna according to thepresent invention.

FIG. 28 is a perspective view showing a slot antenna according to thepresent invention.

FIG. 29 is a block diagram showing an embodiment of an apparatusprovided with the antenna of the present invention.

FIG. 30 is a chart showing an example of a relationship between anantenna form, and directivity and the like.

FIG. 31 is a flow chart showing an example of a procedure for measuringdirectivity, gain, and impedance of an antenna, by changing the form ofthe antenna.

FIG. 32 is a block diagram showing another embodiment of an apparatusprovided with the antenna of the present invention.

FIG. 33 is a block diagram showing still another embodiment of anapparatus provided with the antenna of the present invention.

FIG. 34 is a block diagram showing still another embodiment of anapparatus provided with the antenna of the present invention.

FIG. 35 is a block diagram showing still another embodiment of anapparatus provided with the antenna of the present invention.

FIG. 36 is a perspective view showing an example of an antenna module inwhich the antenna of the present invention and a circuit for controllingthe form of the antenna are integrally provided.

FIGS. 37(a) to 37(c) are perspective views schematically showing thefact that the directivity is changed due to the change in the form ofthe antenna.

FIG. 38 is a block diagram showing an example of a communication systemin which the antenna of the present invention is employed.

FIG. 39 is a block diagram schematically showing a configuration ofcommunication system between the base station and wireless terminals inrespective homes and offices shown in FIG. 38.

FIG. 40 is a block circuit diagram showing the internal constitution ofthe base station in more detail.

BEST MODES FOR CARRYING OUT THE INVENTION

[Antenna of Current Control Type]

First, with reference to FIGS. 1(a) and 1(b), fundamentalcharacteristics of an antenna according to the present invention will bedescribed. Herein, the antenna of “current control type” is described.FIG. 1(a) shows an exemplary configuration of a conventional planerantenna of current control type, and FIG. 1(b) shows an exemplaryconfiguration of a planer antenna of current control type according tothe present invention.

In this specification, the term “an antenna of current control type”indicates an antenna of which the form is designed significantly in viewof the current (electric field) distribution. Other than the antenna ofcurrent control type, there is an antenna of magnetic current controltype. The term “an antenna of magnetic current control type” indicatesan antenna of which the form is designed significantly in view of themagnetic current (magnetic field) distribution.

The conventional planer antenna of current control type includes, asshown in FIG. 1(a), a dielectric substrate 201, and conductors 202 and203 having specified patterns formed on the dielectric substrate 201.The conductors. 202 and 203 are formed by depositing a metal layer on adielectric substrate 1, and then removing unnecessary portions of themetal layer, for example.

In the example shown in the figure, an end portion 102 a of theconductor 202 functions as an input port for an input signal intoequipment in reception, and functions as an output port for an outputsignal from the equipment to the external in transmission.

In the above-described prior-art example, a conductor pattern ispreviously designed so as to obtain desired antenna characteristics, andthe form of the conductors 202 and 203 is fixed on the dielectricsubstrate 201. Thereof, it is extremely difficult to change the form ofthe conductors 202 and 203.

On the other hand, the planer antenna of current control type accordingto the present invention has a cell array structure in which a lot ofunit cells 10 are arranged in rows and columns, for example. Therespective unit cells 10 are separated, but a group of unit cellsselected from the cell array are made to be interconnected by conductingmeans which is not shown in FIG. 1(b), so as to form conductors 2 and 3having a form which functions as an antenna.

In the example shown in FIG. 1(b), the unit cells positioned in aconductive region Rco are interconnected. On the other hand, a group ofunit cells 10 which are not selected from the cell array (a unit cellgroup in a non-conductive region Rnc) are not interconnected at all, orare hardly interconnected. The group of unit cells 10 which are notselected (the unit cell group in the non-conductive region Rnc) is lefton the dielectric substrate, and it is unnecessary to remove the group.This is because a size of each of the isolated unit cells 10 is smallerthan the wavelength of electromagnetic waves, so that the isolated unitcells do not function substantially as part of antenna.

In the example shown in FIG. 1(a), an end portion 2 a of the conductor 2functions as an input port for an input signal into equipment inreception, and functions as an output port for an output signal from theequipment to the external in transmission.

In this invention, after it is determined which unit cells 10 areselected from the array of the unit cells 10, the selected unit cells 10are electrically interconnected by conducting means. In a preferredembodiment of the invention, the unit cells 10 that are not electricallyinterconnected to any other unit cells 10 at a certain point in time(not-selected unit cells) are not removed, and are left on thedielectric substrate. Therefore, in a next occasion, the unit cells 10can be selected and electrically interconnected to other unit cells 10by the conducting means.

As described above, according to the antenna of the present invention,the pattern (the form) of an element functioning as an antenna (anantenna element) can be adjusted.

Generally, when an antenna of current control type is to be designed,the shape of the antenna element is determined so as to obtain a currentpattern corresponding to desired antenna characteristics. In addition tothe conductor pattern, a combination pattern of conductor and dielectricmay function as an antenna. That is, the current flowing through theconductor finally becomes an input signal into the equipment, but theelectromagnetic waves pass also through the dielectric, and thecharacteristics of the dielectric affect the current flowing through theconductor. Therefore, the elements constituting the antenna are both ofthe conductor and the dielectric. However, when a material having anextremely small dielectric constant such as an air exists betweenconductors, the influence by the material on the electromagnetic wavescan be neglected, insofar as the conductors are disposed not in closeproximity to each other. For this reason, only the conductor pattern isdealt as a pattern of antenna element, for convenience.

Hereinafter fundamental differences between the antenna of the presentinvention and the conventional antenna will be described in more detail.

The conventional antenna of current control type shown in FIG. 1(a) is aplaner antenna. Irrespective of the planer type or not, conventionally,the conductor pattern or the combination pattern of conductor anddielectric functioning as an antenna is almost uniquely determined inaccordance with the equipment to which the antenna is attached.

In general, depending on the direction and the frequency band ofelectromagnetic waves to be received, a preferable shape of theconductor portion functioning as an antenna is varied. Accordingly, inthe case of an antenna in which the shape of the conductor portion wasnot dynamically changed (reconstructed), in order to address the changein the direction of electromagnetic waves to be received, it wasnecessary to change the direction of the antenna. In addition, in thecase where the frequency band of the electromagnetic waves to bereceived is changed, a plurality of kinds of antennas corresponding tothe respective frequency bands were previously prepared, and the antennato be used was required to be switched from a certain antenna to anotherantenna in accordance with the change in the frequency band ofelectromagnetic waves.

On the contrary, in the antenna of current control type according to thepresent invention, it is possible to realize a wide variety of conductorpatterns or combination patterns of conductor and dielectric only bychanging the selection of unit cells 10 shown in FIG. 1(b) to beelectrically connected.

For example, in the case where an antenna is attached to a portableinformation terminal in a room, an optimum form of an antenna element isvaried depending on the extent of the room, and the kinds and sizes ofapparatuses placed in the room. In accordance with the variation, theselection of unit cells 10 incorporated in the conductive region Rco inthe cell array shown in FIG. 1(b) is changed, so that the conductorpattern (or the combination pattern of conductor and dielectric) fordefining the form of the antenna can be changed to be optimum.

[Antenna of Magnetic Current Control Type]

Next, a planer antenna of magnetic current control type is described.FIG. 2(a) shows an exemplary configuration of a conventional planerantenna of magnetic current control type. FIG. 2(b) shows an exemplaryconfiguration of a planer antenna of magnetic current control typeaccording to the present invention.

The conventional planer antenna of magnetic current control typeincludes, as shown in FIG. 2(a), a dielectric substrate 201, a conductor205 formed on the dielectric substrate 201. An end portion 205 a of theconductor 205 functions as an input port for an input signal intoequipment in reception, and functions as an output port for an outputsignal from the equipment to the external in transmission. In the caseof the magnetic current control type, the conductor pattern is designedso as to obtain a magnetic current corresponding to desired antennacharacteristics. Similarly to the antenna shown in FIG. 1(a), theconductor 205 is formed from a continuous metal layer, so that it isdifficult to change the shape thereof.

On the other hand, the planer antenna of the magnetic current controltype according to the present invention has, as shown in FIG. 2(b), acell array structure in which a large number of unit cells 10 arearranged in rows and columns, for example. Unit cell groups in the cellarray (unit cell groups in a larger capacity region Ric) are made to bemutually conductive, so that it is easy to form a conductor 5 having adesired shape. Unit cell groups which are not selected from the cellarray (unit cell groups in a smaller capacity region (Rdc) are notconductive at all, or hardly conductive. An end portion 5 a of theconductor 5 functions as an input port for an input signal intoequipment in reception, and functions as an output port for an outputsignal from the equipment to the external in transmission.

The term “magnetic current” does not physically exist. In the case wherean electromagnetic field of high frequencies is studied, the term issupposed as a concept corresponding to an “electric current”. Anoscillating condition of electric charges with respect to an electricfield which temporally varies can be expressed as the “electriccurrent”. Similarly, an oscillating condition of magnetic charges (ormagnetization) with respect to a magnetic field which temporally variescan be grasped as the “magnetic current”.

In the antenna of magnetic current control type according to the presentinvention, similarly to the above-described antenna of current controltype of the present invention, a pattern of element functioning as anantenna (antenna element) can be easily changed. In the antenna ofmagnetic current control type, however, the pattern of antenna elementis adjusted so as to obtain a magnetic current pattern in accordancewith the desired antenna characteristics.

In the antenna of magnetic current control type, similarly to theantenna of current control type of the present invention, not only theconductor pattern, but also a combination pattern of conductor anddielectric can function as an antenna. However, a conductor patternexists in materials having extremely small dielectric constants such asan air, the influence of the materials on electromagnetic waves can bealmost neglected. Thus, only the conductor pattern is dealt as thepattern of antenna element, for convenience.

In the conventional antenna of magnetic current control type, as shownin FIG. 2(a), the conductor pattern functioning as an antenna (or acombination pattern of conductor and dielectric) is determined almostuniquely in accordance with an apparatus to which the antenna isattached.

On the contrary, in the antenna of magnetic current control type of thepresent invention, as shown in FIG. 2(b), a conductor pattern or acombination pattern of conductor and dielectric in accordance with thechange of a wide variety of electromagnetic waves can be easilyrealized. For example, in the case where an antenna is attached to aportable information terminal in a room, an optimum antenna elementpattern is varied depending on the extent of the room, and the kinds andsizes of apparatuses placed in the room. According to the presentinvention, the selection of unit cells 10 incorporated in the largercapacity region Ric in the cell array shown in FIG. 2(b) is changed, sothat the conductor pattern can be changed to be optimum. A differencefrom the antenna of current control type is in that a magnetic currentflowing through a conductor pattern is used as a parameter for judgingwhether an optimum pattern is realized or not in the antenna of magneticcurrent control type.

Generally, the antenna of current control type is configured so as tooscillate an electric field, and the antenna of magnetic current type isconfigured so as to oscillate a magnetic field. However, in actuality,when the electric field is oscillated, the magnetic field is alsooscillated in some degree, and when the magnetic field is oscillated,the electric field is also oscillated in some degree. Therefore, oneantenna may be regarded as an antenna of current control type and anantenna of magnetic current control type.

In the antenna of current control type, when the magnitude and thepattern of a current flowing through the antenna element are determined,the magnitude and the pattern of a magnetic current are accordinglydetermined. On the contrary, in the antenna of magnetic current controltype, when the magnitude and the pattern of a magnetic current flowingthrough the antenna element are determined, the magnitude and thepattern of a current are accordingly determined. In other words, ifeither one of the current or the magnetic current caused in the antennaelement due to the transmission or the reception of electromagneticwaves is controlled, the other one is also controlled. Therefore,antennas are classified into an antenna of current control type and anantenna of magnetic current control type, depending on the judgmentwhich is more convenient, the current or the magnetic current to be usedas a parameter for controlling the pattern of the antenna element, forconvenience. However, these antennas are not substantially different.

The shape of the conductor portion in the antenna of the invention ischanged automatically by the equipment to which the antenna is attached,and also changed by a user as needed. In some cases, a manufacturer mayprepare the cell array constituted by a number of unit cells 10 shown inFIG. 1(b) and FIG. 2(b), and flexibly adjust the form of the antennaelement in assembling or shipping of the product so that the kind ofequipment in which the antenna is used is suitable for the serviceconditions.

The antenna of the present invention is not limited to the planerantenna. For example, a pattern of an antenna element of an apertureantenna or a linear antenna can be controlled. Alternatively, theantenna shown in FIG. 1(b) or FIG. 2(b) can be used as part of anaperture antenna, a linear antenna, or a slot antenna.

EMBODIMENTS OF ANTENNA

Hereinafter embodiments of the antenna according to the presentinvention will be described.

FIRST EMBODIMENT

FIGS. 3(a) and 3(b) are perspective views of a planer antenna of currentcontrol type according to the first embodiment of the present inventionbefore and after the assembling, respectively.

In this embodiment, as shown in FIG. 3(a), a dielectric substrate 1 inwhich a grounding conductor plate 14 is disposed on a back face thereofis first prepared. On the substrate 1, a plurality of conductor elements12 are arranged in a matrix of rows and columns. In this embodiment, amicro strip line 11 which approaches three conductor elements 12 isdisposed on the dielectric substrate 1.

The plane shape of each of the conductor elements 12 in this embodimentis square and the size is the same. In the example shown in FIG. 3(a),twenty-four conductor elements 12 are arranged in a region having asubstantially square outline. However, the arrangement pattern of theconductor elements is not limited to this. In addition, the shapes andthe sizes of the respective conductor elements 12 are not necessarilyset to be equal to each other on one dielectric substrate 1.

A length a of one side of each conductor element 12 is set to be smallerthan a wavelength of electromagnetic waves to be handled. Morespecifically, in the case where electromagnetic waves of 100 GHz (awavelength of about 3 mm) are handled, for example, the length a of theconductor element 12 is set to be about 1.5 mm, for example. On theother hand, a thickness of the conductor element 12 is determined to bea sufficient thickness for satisfying the electric power and theimpedance matching property of the electromagnetic waves to betransmitted or received.

The conductor elements 12 in the condition shown in FIG. 3(a) aremutually separated, and any electric connection is not formed. If thedielectric substrate 1 in this stage is irradiated with electromagneticwaves, a current required for transmitting or receiving theelectromagnetic waves is not generated in the array of the conductorelements 12 because each of the conductor elements 12 is smaller thanthe wavelength. Thus, the respective conductor elements 12 in thecondition shown in FIG. 3(a) do not function as an antenna.

In order to constitute an antenna by using the conductor elements 12,coupling means for electro-magnetically coupling arbitrary conductorelements 12 is required. In the example shown in FIG. 3(b), a connectingelement 13 is used as the coupling means.

The connecting element 13 is disposed on adjacent two conductor elements12 so as to overlap the conductor elements 12 in the example shown inFIG. 3(b). The concrete configuration and the forming method of theconnecting element 13 will be described later in detail.

When electromagnetic waves are to be transmitted or received, some ofthe plurality of connecting elements 13 electrically interconnect thecorresponding adjacent conductor elements 12, and the other connectingelements 13 do not electrically interconnect the corresponding adjacentconductor elements 12. For example, the connecting elements 13 which arehatched in FIG. 3(b) cause the adjacent conductor elements 12 to beconductive, but the other connecting elements 13 do not cause theadjacent conductor elements 12 to be conductive. Therefore, a conductorpattern shown in a lower right portion of FIG. 3(b) is formed on thesubstrate 1.

As described above, in the present invention, an array of the conductorelements 12 are first formed on the dielectric substrate 1, and thenconductor elements 12 which are appropriately selected from the array ofthe conductor elements 12 are electrically interconnected, so as to forma conductor pattern which functions as at least part of an antenna.

In the example shown in FIG. 3(a), conductor elements 12 each having asubstantially square plane shape are arranged in a matrix of rows andcolumns. In the antenna of the present invention, the plane shape ofeach conductor element 12 is not limited to be square. For example, asshown in FIG. 4(a), an array of conductor elements 12 each having aplane shape of regular hexagon may be used. Alternatively, an array ofconductor elements 12 each having a rectangular shape shown in FIG.4(b), or an array of conductor elements 12 each having a circular shape(or an elliptical shape) shown in FIG. 4(c) may be adopted. In addition,a conductor element having a triangle shape, or other polygonal shapescan be used.

After a metal film is formed on the dielectric substrate 1, the metalfilm is worked, so that a plane shape and a plane layout of conductorelements 12 can be arbitrarily set. The surface (the upper face) of eachconductor element 12 shown in the figure is flat. Alternatively,unevenness may exist on the surface.

All of the conductor elements 12 which constitute an antenna do notnecessarily have the same size. As shown in FIG. 5(a), sizes and shapesof conductor elements 12 may vary depending on the positions thereof onthe dielectric substrate 1.

FIG. 5(b) shows an improved example of the shape of a conductor memberfunctioning as an input/output port. As shown in the figure, a conductorstrip having a size of about wavelength of electromagnetic waves or moremay exist in the inside of the array of the conductor elements 12.

FIG. 5(c) shows an example in which conductor elements 12 havingdifferent sizes and plane shapes mixedly exist in one array of conductorelements. Also in this case, the sizes (the length of a longer side inthe case of a rectangle) of the respective conductor elements 12 are setto be smaller than the wavelength of radio waves to be transmitted andreceived.

FIG. 6(a) shows an exemplary arrangement in which the arranged directionof conductor elements 12 is inclined by 45 degrees with respect to thearranged direction of the conductor elements 12 in the other examples.

FIG. 6(b) shows an example in which a plurality of conductor strips 11capable of functioning as an input/output port are disposed. In thiscase, depending on the position of a circuit to be connected to theantenna, a conductor strip 11 in an appropriate position is selected asthe input/output port.

FIG. 6(c) shows an example in which a conductor member functioning as aninput/output port is positioned in a center portion instead of theperipheral portion of the dielectric substrate 1. In this example, theconductor member functioning as the input/output port is connected to anexternal circuit via a VIA disposed in the dielectric substrate.

In the antenna of the present invention, the arrangement pattern of theconductor elements 12 is arbitrary, and is not limited to theabove-described kinds of exemplary arrangements. Alternatively, a groundelectrode of a coplanar type line may be formed by a plurality ofconductor elements 12.

Hereinafter examples of means for selecting arbitrary conductor elements12 from an array of a plurality of conductor elements 12 arranged asdescribed above, and for mutually connecting them will be described.

FIRST CONCRETE EXAMPLE

First, FIG. 7 is referred to. In the example shown in FIG. 7, theposition of the connecting element 13 is changed by an actuator.Specifically, the connecting element 13 is driven in a normal directionof a main face of the substrate 1 by a control system 15 provided withan actuator such as a solenoid coil, a switch, and a power supply. Theconnecting element 13 can reciprocate between a first position in whichthe connecting element 13 is in contact with adjacent two conductorelements 12 and a second position in which the connecting element 13 isnot in contact with them. The connecting element 13 in the firstposition electrically connects the corresponding two conductor elements12, but the connecting element 13 in the second position electricallyseparates the corresponding two conductor elements 12. For the array ofthe plurality of conductor elements 12, a plurality of connectingelements 13 are selectively moved by the control system 15, so that theform of the antenna element can be dynamically reconstructed.

As the actuator for moving the connecting element 13, other than theactuator utilizing the solenoid coil, an actuator utilizingpiezoelectricity, an actuator by static electricity, and an actuator byshape memory alloy can be used. Such actuators can be suitablyfabricated by using micro work techniques for producing a micro machine.The above-described actuator functions as a switching element forswitching the electrically conductive/non-conductive conditions betweenat least two conductor elements.

Instead of the change of a pattern (form or plane layout) of the antennaelement by using the control system 15 by a user or a manufacturer of anapparatus provided with the antenna (a portable terminal, for example),an inner circuit of the apparatus provided with the antenna candynamically and automatically change the form of the antenna elementdepending on the conditions.

SECOND CONCRETE EXAMPLE

Next, FIG. 8 is referred to. In the example shown in FIG. 8, a conductorpiece functioning as a connecting element 13 for electrically connectingconductor elements 12 is disposed only in a selected position in anarray of the conductor elements 12. For conductor elements 12 to beelectrically separated, any conductor piece is not disposed in aposition overlapping them. As such a conductor piece, a short stripformed of a metal such as aluminum can be used. The contact between theconductor piece and the conductor elements 12 may be realized by using aconductive adhesive, for example.

In this example, the position of the connecting element 13 is notchangeable. Thus, the connection pattern of the conductor elements 12 isnot dynamically changed. Accordingly, in this example, it may bedifficult for a user to change the form of the antenna. However,according to the example shown in FIG. 8, a manufacturer of an apparatusprovided with the antenna can optimize the form of the antenna elementin a condition where the inner circuit of the apparatus is electricallyconnected to the antenna in a production stage of the apparatus. Thecharacteristics of the antenna also vary depending on thecharacteristics of a circuit to be connected. Therefore, it is difficultto evaluate the characteristics of the antenna, and to determine theoptimum form independently in view of the antenna. If a conventionalantenna is incorporated in an apparatus and connected to a circuit, thecharacteristics of the antenna can be evaluated, but it is difficult tochange the form of the antenna. On the other hand, in the example shownin FIG. 8, the connecting element 13 can be relatively easily detached.

In FIGS. 7 and 8, one connecting element 13 overlaps two conductorelements 12. Alternatively, the connecting element 13 may overlap threeor more conductor elements 12.

THIRD CONCRETE EXAMPLE

Next, FIG. 9 is referred to. In the example shown in FIG. 9, a switchingtransistor 13 a is formed between two adjacent conductor elements 12.The switching transistor 13 a is selectively turned on or off, so thatelectric connection/non-connection conditions between the correspondingtwo conductor elements 12 can be controlled.

In FIG. 9, each switching transistor 13 a includes a source S, a drainD, and a gate G. By adjusting an electrical potential at the gate G, theelectric conductive/non-conductive conditions between the source S andthe drain D can be switched. Each switching transistor 13 a is formedfrom a thin film transistor, for example. The switching transistors 13 aare arranged on a substrate 1 in a matrix. In order to selectivelyoperate such switching transistors 13 a, a driving circuit which is notshown is used. The driving circuit controls the operation of theplurality of switching transistors 13 a, so as to select necessaryconductor elements 12 and to mutually and electrically connect them,thereby forming a desired form of the antenna element.

In FIG. 9, for the sake of clarity, a transistor 13 a is disposed on anupper side (on the side of a transmitting and receiving face forelectromagnetic waves) of the conductor elements 12. In actuality, it ispreferred that the transistor 13 a be formed on a lower side of theconductor elements 12. This is because the wiring for mutuallyconnecting the transistors 13 a does not badly affect the transmissionand reception of electromagnetic waves.

Instead of a voltage signal, the switching device such as the transistor13 a may be controlled by an optical signal. In such a case, a switchingdevice in which the electric conductive/non-conductive condition isswitched by irradiation of light is used. In an array of such switchingdevices, switching devices which are appropriately selected areirradiated with light, so that the connection pattern of conductiveelements 12 can be freely set.

SECOND EMBODIMENT

With reference to FIG. 10, a second embodiment of the planer antennaaccording to the present invention will be described.

The antenna shown in FIG. 10 is different from the antenna shown in FIG.8 in that a dielectric film 17 formed from a plastic film or the like isdisposed on conductor elements 12. Among a plurality of connectingelements 13, the selected connecting elements 13 are disposed closer tothe conductor elements 12 via the dielectric film 17. However, theconnecting elements 13 which are not selected are relatively distantfrom the conductor elements 12.

With reference to FIG. 11, the operation of the antenna shown in FIG. 10is described. The connecting elements 13 are not directly in contactwith the corresponding conductor elements 12 due to the existence of thedielectric film 17,but an electric capacity between the correspondingconductor elements 12 and the connecting element 13 is relatively high.Therefore, a displacement current is caused to flow between them in anelectromagnetic field of high frequencies. Due to the displacementcurrent, a condition where a current can flow between adjacent conductorelements 12 via the connecting element 13 is realized. In the case wherethe connecting elements 13 are relatively distant from the dielectricfilm 17, an electric capacity between the conductor elements 12 and theconnecting element 13 is reduced, so that the displacement current isalso reduced. Therefore, the connecting element 13 in such a positiondoes not electrically connect the corresponding two connecting elements13, substantially.

As described above, even if the dielectric film 17 is interposed betweenthe conductor elements 12 and the connecting element 13, the separatedconductor elements 12 can be electrically connected by the displacementcurrent flowing via the connecting element 13.

In FIG. 11, a connecting element 13 which is not used for electricallyconnecting the conductor elements 12 is shown above the dielectric film12. Another dielectric film may be formed between the connecting element13 and the dielectric film 12 which are distant from each other. In sucha case, the distance between the connecting element 13 and the conductorelements 12 cannot be varied. Instead of such a configuration, theconnecting element 13 may be driven by an actuator such as shown in FIG.7, for example. With such a configuration, the combination of conductorelements 12 between which a displacement current flows can bedynamically changed by changing the position of the connecting element13, as required.

As shown in FIG. 8, a connecting element 13 is selectively disposed in aportion of the dielectric film 17 under which the conductor elements 12are to be conductive, thereby electrically connecting the selectedconductor elements 12. In such a case, in a production process of anapparatus provided with an antenna, an antenna element having an optimumform can be easily manufactured.

In addition, a switching transistor 13 a shown in FIG. 9 can be used asthe connecting element 13. By turning on or off the switching transistor13 a, a condition where the conductor elements 12 are conductive and acondition where the conductor elements 12 are not conductive can bedynamically switched.

THIRD EMBODIMENT

FIG. 12(a) is a perspective view showing an appearance structure of aplaner antenna of current control type of the third embodiment accordingto the present invention. FIG. 12(b) is a perspective view showing astructure in which a dielectric substrate and conductor elements areremoved from the antenna of this embodiment.

Also in this embodiment, as shown in FIG. 12(a), on a dielectricsubstrate 1 in which a grounding conductor plate 14 is disposed on aback face thereof, conductor elements 12 each having a squareplane-shape are arranged in an array. A length a of one side of eachconductor element 12 is smaller than a wavelength of electromagneticwaves to be handled. For example, in the case where a signal of about100 GHz (a wavelength of about 3 mm) is handled, the length a of theconductor element 12 is about 1.5 mm. The thickness of the conductorelement 12 is determined to be a thickness sufficient for satisfying thepower and the impedance matching property of the electromagnetic wavesto be transmitted and received. On the dielectric substrate 1, a microstrip line 11 is disposed so as to approach three conductor elements 12.

As shown in FIG. 12(b), under the array of the conductor elements 12, aconnecting element 13 which overlaps adjacent two conductor elements 12is disposed. The connecting element 13 does not appear in FIG. 12(a)because the connecting element 13 is covered with the conductor elements12 and the dielectric substrate 1, but the connecting element 13 isdisposed in a recessed portion formed in the dielectric substrate 1.Under the connecting element 13, an actuator 18 for vertically drivingthe connecting element 13 is attached. There are several kinds ofactuators 18, and the specific configurations thereof will be describedbelow. In order to control (or adjust) the current so as to have adesired magnitude and pattern, similarly to the first embodiment, someof the connecting elements 13 make the corresponding conductor elements12 on both sides thereof to be conductive, and the other connectingelements 13 make the corresponding conductor elements 12 on both sidesthereof to be non-conductive.

Also in this embodiment, as in the second embodiment, a dielectric filmmay be interposed between the connecting elements 13 (or 13′) and theconductor elements 12 (or 12′).

Next, examples of means for controlling the conductive/non-conductiveconditions of the conductor elements 12 by the connecting element 13will be described. Also in this embodiment, the non-conductive conditionincludes a condition where a weak current which cannot be utilized as asignal flows.

FIRST CONCRETE EXAMPLE

FIGS. 13(a) and 13(b) are sectional views showing the configuration ofan actuator in the first example of the third embodiment. As shown inthe figures, in this example, the actuator is constituted by a solenoidcoil, a spring, and the like. The actuator is constituted in such amanner that, by the control of a circuit in which a switch and a powersupply are disposed, a condition where the connecting element 13 is incontact with the conductor elements 12 (see FIG. 13(b)) and a conditionof non-contact (see FIG. 13(a)) are switched. In the case of thisexample, a user can directly adjust the pattern of an antenna element,or an inner circuit can automatically control the pattern of the antennaelement to be an appropriate pattern.

SECOND CONCRETE EXAMPLEd

FIGS. 14(a) and 14(b) are sectional views showing the configuration ofan actuator in a second example of the third embodiment. As shown in thefigures, in this example, the actuator is constituted by a lever whichcan be rotated with respect to a fulcrum, and a supporting bar, disposedrotatably by the lever, for supporting a connecting element 13, and thelike. The actuator is constituted in such a manner that, by the controlof a circuit including a switch, a power supply, and the like, acondition where the connecting element 13 is in contact with theconductor elements 12 (see FIG. 14(b)), and a condition of non-contact(see FIG. 14(a)) are switched. In the case of this example, a user candirectly adjust the pattern of an antenna element, or an inner circuitcan automatically control the pattern of the antenna element to be anappropriate pattern.

THIRD CONCRETE EXAMPLE

FIGS. 15(a) and 15(b) are sectional views showing the configuration ofan actuator in a third example of the third embodiment. As shown in thefigures, in this specific example, the actuator is constituted by alever which can rotate with respect to a fulcrum, a supporting bar,disposed rotatably by the lever, for supporting the connecting element13, and the like. The lever is formed by horizontally bonding two plateshaving different piezoelectric coefficients together. In this case, thematerials are selected so that the plate on the lower side is moreextended than the plate on the upper side when a potential flows.Therefore, when electricity flows through the two plates, the lever iswarped to the upper side. The lever is constituted in such a mannerthat, by the control of a circuit provided with a switch, a powersupply, and the like, a condition where the connecting element 13 is incontact with the conductor elements 12 (see FIG. 15(b)) and a conditionof non-contact (see FIG. 15(a)) are switched. In the case of thisexample, a user can directly adjust the pattern of an antenna element,or an inner circuit can dynamically and automatically control thepattern of the antenna element to be an appropriate form.

FOURTH EMBODIMENT

FIG. 16 is a perspective view showing a fourth embodiment of an antennaaccording to the present invention.

In this embodiment, as shown in FIG. 16 on a dielectric substrate 1 inwhich a grounding conductor plate 14 is disposed on a back face thereof,conductor elements 12 each having a square plane shape are arranged inan array. In addition, on the conductor elements 12, a dielectricsubstrate 1′ and connecting elements 13′ and actuators 18′ are disposed.In addition, conductor elements 12′ which overlap the respectiveconnecting elements 13′ are laminated above the connecting elements 13′.As the actuators 18′, actuators which are described above in the thirdembodiment can be utilized. Instead of the actuators 18′, a mechanismfor switching the conductive/non-conductive conditions described in thefirst embodiment can be disposed.

Also, as described in the second embodiment, a dielectric film may beinterposed between the connecting elements 13 (or 13′) and the conductorelements 12 (or 12′).

In this embodiment, a plurality of layers in which a plurality ofconductor elements 12 and 12′ are arranged are laminated, and theelectrical conductive condition between the conductor elements 12 and12′ in the respective layers can be controlled by the actuators 18′ orthe like in the laminated direction. Therefore, by the antenna of thisembodiment, a three-dimensional current distribution can be realized.

In the first to fourth embodiments, examples in which the conductorelements 12, the connecting elements 13, the actuators, and the like areregularly arranged are described. The arranged way, and the shape of theconductor 2 can be varied depending on the respectively desired antennacharacteristics so as to realize the characteristics.

FIFTH EMBODIMENT

FIG. 17 is an exploded perspective view showing a fifth embodiment of aplaner antenna according to the present invention. FIG. 18 is aperspective view showing a general appearance of the antenna. Theantenna of the fifth embodiment is of a magnetic current control type.

For the purpose of easily understanding the structure, FIG. 17 shows acondition where conductor elements 12 and strip lines 11 are removedfrom a dielectric substrate 1. FIG. 18 shows the structure in which theconductor elements 12 and the strip lines 11 are disposed on thedielectric substrate 1.

In this embodiment, as shown in FIG. 18, on the dielectric substrate 1in which a grounding conductor plate 14 is disposed on a back facethereof, conductor elements 12 each having a square plane shape arearranged in an array. On the dielectric substrate 1, a micro strip line11 is disposed so as to approach three conductor elements 12. A length aof one side of each of the conductor elements 12 is smaller than thewavelength of the electromagnetic waves to be handled. In the case wherea signal of about 100 GHz is handled, for example, the length a of aconductor element 12 is about 1.5 mm. The thickness of a conductorelement 12 is determined to be sufficient for satisfying the electricpower and the impedance matching property of the electromagnetic wavesto be transmitted and received.

Under the conductor elements 12, as shown in FIG. 17, dielectricelements 20 interposed between the respective conductor elements 12 andthe grounding conductor plate 14 are disposed. The dielectric elements20 are formed by patterning from the dielectric substrate 1 togetherwith a recessed portion 19. FIG. 17 shows three kinds of dielectricelements 20 having different plane areas. In this embodiment, as shownin FIGS. 19(a) and 19(b), for the case where a first dielectric element20 a having the same plane area as that of the conductor element 12 anda first dielectric element 20 b having a smaller plane area than that ofthe conductor element 12, a magnetic current to be generated isdescribed.

FIGS. 19(a) and 19(b) are a sectional view and a plan view of a planerantenna in which three first dielectric elements 20 a exist under threeconductor elements 12. As shown in FIG. 19(a), between the respectiveconductor element 12 and the grounding conductor film 14, the firstdielectric element 20 a having a larger area is interposed, so that alarge displacement current is caused to flow between the respectiveconductor element 12 and the grounding conductor film 14 because of alarge electric capacity. As a result, as shown in FIG. 19(b), a magneticcurrent surrounding the three conductor elements 12 is formed.

FIGS. 20(a) and 20(b) are a sectional view and a plan view of an antennain which first dielectric elements 20 a having a larger area exist undertwo conductor elements 12 on both ends of three conductor elements 12,and a second dielectric element 20 b having a smaller area exists underthe center conductor element 12. Generally, in the case where only aninsulator having an extremely small specific inductive capacity existsbetween two conductors, only a small displacement current is caused toflow between the two conductors because of the reduction in electriccapacity. That is, a magnetic current is hardly generated around thecenter conductor element 12, so that the magnetic currents caused aroundthe conductor elements 12 on both ends are not coupled. As a result, asshown in FIG. 20(b), isolated magnetic currents surrounding only theconductor elements 12 on both ends are formed.

As described above, the control (or adjustment) of the magnetic currentpatterns as shown in FIGS. 19(b) and 20(b) can be performed.

SIXTH EMBODIMENT

An antenna of this embodiment has substantially the same structure ofthe antenna shown in FIGS. 17 and 18. Instead of the capacitiveinsulating films 20 a and 20 b in the fifth embodiment, the antenna ofthis embodiment includes a first dielectric element 21 a having arelatively high specific inductive capacity ε 1, and a second capacitiveinsulating film 21 b having a relatively low specific inductive capacityε 2.

FIGS. 21(a) and 21(b) are a sectional view and a plan view of a planerantenna in which three first dielectric elements 20 a exist under threeconductor elements 12. As shown in FIG. 21(a), a first dielectricelement 21 a having a higher specific inductive capacity ε 1 existsbetween the respective conductor element 12 and the grounding conductorfilm 14, so that a large displacement current is caused to flow betweenthe respective conductor element 12 and the grounding conductor film 14because of a large electric capacity. As a result, as shown in FIG.21(b), a magnetic current surrounding the three conductor elements 12 isformed.

FIGS. 22(a) and 22(b) are a sectional view and a plan view of an antennain which first dielectric elements 21 a having a higher dielectricconstant ε 1 exist under two conductor elements 12 on both ends of threeconductor elements 12, and a second dielectric element 21 b having aspecific inductive capacity ε 2 lower than ε 1 exists under the centerconductor element 12. Generally, in the case where only an insulatorhaving an extremely small specific inductive capacity is interposedbetween two conductors, only a small displacement current is caused toflow between the two conductors because of the reduction in electriccapacity. That is, a magnetic current is hardly caused around the centerconductor element 12, so that the magnetic currents caused around theconductor elements 12 on both ends are not coupled. As a result, asshown in FIG. 22(b), isolated magnetic currents surrounding therespective conductor elements 12 on both ends are formed.

As described above, the control (or adjustment) of the magnetic currentpatterns as shown in FIGS. 21(b) and 22(b) can be performed.

SEVENTH EMBODIMENT

The antenna of magnetic current control type of this embodiment hassubstantially the same structure as that shown in FIGS. 17 and 18.Instead of the respective dielectric elements 20 a and 20 b in the fifthembodiment, the antenna of this embodiment includes a first dielectricelement 23 a having a higher averaged specific inductive capacity and asecond dielectric element 23 b having a lower averaged specificinductive capacity. Each of the first dielectric element 23 a and thesecond dielectric element 23 b is constituted by a first insulator 22 ahaving a higher specific inductive capacity ε 1 and a second insulator22 b having a lower specific inductive capacity ε 2. In the firstdielectric element 23 a, a ratio of the first insulator 22 a is largerthan that of the second insulator 22 b. In the second dielectric element23 b, a ratio of the second insulator 22 b is larger than that of thefirst insulator 22 a.

FIGS. 23(a) and 23(b) are a sectional view and a plan view of a planerantenna in which three first dielectric elements 23 a exist under threeconductor elements 12. As shown in FIG. 23(a), the first dielectricelements 23 a having a higher averaged specific inductive capacity existbetween the respective conductor elements 12 and the grounding conductorfilm 14, so that a large displacement current is caused to flow betweenthe respective conductor elements 12 and the grounding conductor film 14because of a large electric capacity. As a result, as shown in FIG.23(b), a magnetic current surrounding the three conductor elements 12 isformed.

FIGS. 24(a) and 24(b) are a sectional view and a plan view of an antennain which first dielectric elements 23 a having a higher averagedspecific inductive capacity exist under two conductor elements 12 onboth ends of three conductor elements 12, and a second dielectricelement 23 b having a lower averaged specific inductive capacity existsunder the center conductor element 12. Generally, in the case where onlyan insulator having an extremely small specific inductive capacity isinterposed between two conductors, only a small displacement current iscaused to flow between the two conductors because of the reduction inelectric capacity. That is, a magnetic current is hardly caused aroundthe center conductor element 12, so that the magnetic currents causedaround the conductor elements 12 on both ends are not coupled. As aresult, as shown in FIG. 24(b), isolated magnetic currents surroundingonly the respective conductor elements 12 on both ends are formed.

As described above, the control (or adjustment) of the magnetic currentpatterns as shown in FIGS. 23(b) and 24(b) can be performed.

EIGHTH EMBODIMENT

An antenna of magnetic current control type of this embodiment hassubstantially the same structure as that of FIGS. 17 and 18. Instead ofthe dielectric elements 20 a and 20 b the fifth embodiment, the antennaincludes dielectric elements 20 having the same area and specificinductive capacity.

FIGS. 25(a) and 25(b) are a sectional view and a plan view of a planerantenna in which three conductor elements 12 are in contact with thedielectric elements 20, respectively. As shown in FIG. 25(a), only thedielectric elements 20 are interposed between the respective conductorelements 12 and the grounding conductor film 14, so that a largedisplacement current is caused to flow between the respective conductorelements 12 and the grounding conductor film 14 because of the largeelectric capacity. As a result, as shown in FIG. 25(a), a magneticcurrent surrounding the three conductor elements 12 is formed.

FIGS. 26(a) and 26(b) are a sectional view and a plan view of an antennain which two conductor elements 12 on both ends of three conductorelements 12 are in contact with the dielectric elements 20, but thecenter conductor element 12 is separated from the dielectric element 20.Generally, in the case where only an insulator having an extremely smallspecific inductive capacity such as an air is interposed between twoconductors, only a small displacement current is caused to flow betweenthe two conductors because of the reduction in electric capacity. Thatis, a magnetic current is hardly caused around the center conductorelement 12, so that the magnetic currents caused around the conductorelements 12 on both ends are not coupled. As a result, as shown in FIG.26(b), isolated magnetic currents only surrounding the respectiveconductor elements 12 on both ends are formed.

As described above, the control (or adjustment) of the magnetic currentpatterns as shown in FIGS. 25(b) and 26(b) can be performed.

The control (or adjustment) between the contact and the non-contact ofthe conductor element 12 with the dielectric element 20 can be easilyrealized by utilizing an actuator described in each examples in thethird embodiment, for example.

ANOTHER EMBODIMENT RELATING TO THE STRUCTURE OF ANTENNA

The antenna of the present invention can be applied to an apertureantenna such as a parabolic antenna and a reflective mirror antenna, alinear antenna such as a dipole antenna and a patch antenna, and a slotantenna, for example, in addition to the planer antenna.

FIG. 27 is a view schematically showing an exemplary structure of thecase where the present invention is applied to a horn antenna. As shownin the figure, a large number of conductor elements 12 are disposed inan array on an inner face of the horn antenna. Similarly to theabove-described first to fourth embodiments, the control (or adjustment)for switching the conductor elements 12 through which a current flows (ahatched portion in the figure) and the conductor elements 12 throughwhich any current does not flow is performed. Thus, it is possible torealize a horn antenna of current control type which can address thechange of various electromagnetic waves.

FIG. 28 is a view schematically showing an exemplary structure of thecase where the present invention is applied to a slot antenna. As shownin the figure, a large number of conductor elements 12 are disposed inan array on an inner face of the slot antenna. Similarly to theabove-described first to fourth embodiments, the control (or adjustment)for switching the conductor elements 12 through which a current flows (ahatched portion in the figure) and the conductor elements 12 throughwhich any current does not flow is performed. Thus, it is possible torealize a slot antenna of current control type or magnetic currentcontrol type which can address the change of a wide variety ofelectromagnetic waves.

Alternatively, respective conductor portions of a linear antenna such asa Yagi antenna, or a number of conductor elements on a curved face of aparabolic antenna having the curved face are disposed in an array, andthe flow of a current to the respective conductor elements iscontrolled, whereby it is possible to realize an antenna of currentcontrol type which can address the change of a wide variety ofelectromagnetic waves.

EMBODIMENTS OF APPARATUS PROVIDED WITH THE ANTENNA

Hereinafter, embodiments of apparatuses provided with antenna accordingto the present invention will be described. The following embodimentsdescribe exemplary antennas including switching elements which candynamically change the connection of conductor elements as conductingmeans.

NINTH EMBODIMENT

FIG. 29 is a block circuit diagram showing an embodiment of an apparatusprovided with an antenna of the present invention.

The apparatus of this embodiment includes, as shown in FIG. 29, theabove-described antenna 50 of the present invention, a communicationcircuit 61 connected to the antenna 50, and a controller for controllingthe form of the antenna 50.

The apparatus further includes a driver 51 for driving conducting means(not shown) included in the antenna 50, a designing section 53 fordetermining the form of the antenna, a form design controller (topologysearch controller) 54 for controlling the driver 51, and a memory 55 forstoring information on the antenna. The information on the antennastored in the memory 55 includes physical sizes (area, thickness, andthe like) of a conductor element, a dielectric element, a connectingelement, a dielectric substrate, and the like, and initial conditions ofthe form of the antenna 50.

The apparatus further includes a level detector 71 for detecting a levelof a signal transmitted and received by the antenna 50, a directivitycheck section 72 for checking the directivity of the antenna 50 based onthe level of the signal detected by the level detector 71, a gain checksection 73 for checking the gain from the detected level of the signal,and an impedance check section 74 for checking the impedance matchingproperty of the antenna 50 and the communication circuit 61 from thedetected level of the signal. The term “check” in this specification mayinclude an operation for measuring physical quantities relating to thedirectivity, the gain, and the impedance.

Next, the operation of the apparatus will be described.

First, the form designing section 53 determines the initial form of theantenna 50 based on the information stored in the memory 55. Based onthe designed result by the form designing section 53, the form designcontroller 54 controls the driver 51 so that the antenna 50 has the sameform as the designed form. The driver 51 drives the conducting means sothat the respective elements of the antenna 50 form the desired antennaform.

Since the antenna 50 can be used for transmission and reception, it isdesired that the optimization of the form of the antenna 50 beindependently performed for the antenna for transmission and for theantenna for reception.

Hereinafter the procedure for adjusting the form in the case where theantenna 50 is used as an antenna for transmission is described.

First, the communication circuit 61 transmits a signal for transmissionto the antenna 50. The signal is also input into the level detector 71.In this embodiment, on a signal path between the communication circuit61 and the antenna 50, a member for directional coupling for a highfrequency signal is disposed. Therefore, it is possible to perform theadjustment in such a manner that, if a signal is sent from thecommunication circuit 61 to the antenna 50, the signal reflected fromthe antenna 50 to the communication circuit 61 is not returned. Thelevel detector 71 can detect both of the level of the signal transmittedfrom the communication circuit 61 to the antenna 50 and the level of thesignal reflected from the antenna 50.

The directivity check section 72 determines whether the directivity ofthe antenna 50 in transmission is in an allowable range or not, based onthe level of the high frequency signal detected by the level detector71. Specifically, in the case where the level of the signal reflectedfrom the antenna 50 is varied depending on the direction of the antenna50, if the difference in level of the reflected signals in therespective directions is in a certain range, it is determined that thedirectivity is in the allowable range. If the difference is not in thecertain range, it is determined that the directivity is not in theallowable range. In this way, the directivity in the transmission of theantenna 50 is checked. There exist a case where it is desired that thedirectivity be as low as possible and a case where it is desired thatthe directivity be as high as possible. Therefore, the range used forchecking the directivity may vary depending on the kind and applicationof the equipment to which the antenna is applied, and the purpose ofreception or transmission.

The gain check section 73 checks the gain of the antenna 50 based on acondition whether the ratio of the level of the transmitted signal fromthe communication circuit 61 and to the level of the signal reflectedfrom the antenna 50 is in the allowable range, or not, and otherconditions. Generally, it is desired that the ratio of the level of thetransmitted signal to the level of the reflected signal be as high aspossible. Thus, if the ratio is a certain value or more, it isdetermined that the gain is good.

The impedance check section 74 checks the impedance matching between thecommunication circuit 61 and the antenna 50, based on a conditionwhether the ratio of the level of the signal output from thecommunication circuit 61 to the level of the signal reflected from theantenna 50 is in an allowable range, or not, and other conditions.Generally, a high ratio of the level of the reflected signal to thelevel of the input signal to the antenna 50 means that the impedancematching is not realized. Therefore, if the ratio in level is a certainvalue or more, it is determined that the impedance matching property isgood.

Preferably, until it is determined that all of the directivity, thegain, and the impedance matching property are good, the designing of theform of the antenna is repeatedly performed in the form designingsection 53, and the form of the antenna 50 is dynamically reconstructedvia the form design controller 54 and the driver 51. When it iseventually determined that all of the directivity, the gain, and theinput impedance matching property are good, information (data) relatingto the form is stored in the memory 55.

There may be a case where it is sufficient that all of the directivity,the gain, and the impedance matching property are not determined to begood. Alternatively, there may be a case where the form of the antenna50 is optimized in a mode in which the directivity is emphasized, andthe gain is neglected.

FIG. 30 shows an example of relationships between the antenna form, andthe directivity and the like. In FIG. 30, the symbol “{circle over (◯)}”indicates that it is excellent, and the symbol “◯” indicates that it issuperior. The symbol “Δ” indicates that it is common. For example, theantenna having an antenna element which straightly extends as a line inFIG. 30 is superior in impedance, but is common in the directivity andthe gain.

In this embodiment, based on the data stored in the memory 55, theconducting means of the antenna 50 is driven so that the couplingpattern of the conductor elements in the antenna 50 sequentially takes aplurality of kinds of forms which are previously set. For example, aplurality of forms including the three forms shown in FIG. 30 aresequentially realized in the antenna 50. In the respective forms, thedirectivity, the gain, and the impedance matching property areevaluated, and the evaluated results are stored in the memory. In FIG.30, the evaluated results are shown by using the symbols such as “◯” and“Δ”. In actuality, each parameter is evaluated by using a numericalvalue. The evaluated results obtained as described above are assigned tothe various forms of the antenna, and a look-up table is generated, sothat it is possible to select an optimum form from the table inaccordance with the conditions.

FIG. 31 is a flowchart showing the above-described procedure. First, inStep S1, the communication circuit starts the transmission of apredetermined signal. In Step S2, among a plurality of forms which canbe taken by the antenna, a form selected as an initial form (N=1, i.e.,the first form) is applied to the antenna. In Step S3, a reflectedsignal from the antenna having the form is detected. In Step S4, thedirectivity, the gain, and the impedance are measured. In Step S5,respective values of the directivity, the gain, and the impedanceobtained by the measurement are stored in the memory as data of N=1.

Next, a form selected as the second form of N=2 is applied to theantenna, and then the operation of Steps S2 to S5 is repeated. The sameoperation is repeated a required number of times from the third form ofN=3, so that measured results of the directivity, the gain, and theimpedance can be obtained for all of or part of the forms which can betaken by the antenna.

These measured results are stored in the memory, so that a preferableform can be selected as needed in accordance with the conditions. If thecontents of the memory are displayed on a display, a user can select theform of the antenna, based on the displayed contents. Alternatively,based on the contents of the memory, an antenna control apparatus mayautomatically determine the form of the antenna.

Next, a procedure for adjusting the form in the case where the antenna50 is used as an antenna for reception will be described.

When a signal from external equipment is sent, the antenna 50 receivesthe signal, and the level of the received high frequency signal isdetected by the level detector 71. As the external equipment, equipmentwhich is especially designed for test can be used, but any othercommunication equipment can be used. When the apparatus of thisembodiment is a device such as a portable information terminal, it ispossible to optimize the antenna form by utilizing a signal which ispublicly sent.

The directivity check section 72 determines whether the directivity inreception of the antenna 50 is in the allowable range, or not, based onthe level of the received high frequency signal. Specifically, in thecase where the level of a signal received by the antenna 50 variesdepending on the direction of the antenna 50, if a difference in levelof the received signals in respective directions is in a certain range,it is determined that the directivity is in the allowable range.Conversely, if the difference is not in the certain range, it isdetermined that the directivity is not in the allowable range. In thisway, the directivity in reception of the antenna 50 is checked. Also inthis case, there may be a case where it is desired that the directivityis as low as possible, and a case where it is desired that thedirectivity is as high as possible. Therefore, the range which is usedfor determining the directivity may be varied depending on the kinds andapplication of the equipment in which the antenna is used, and thepurpose of reception or transmission.

In the case where the apparatus of this embodiment communicates withanother communication equipment via an antenna, a preferred form of theantenna 50 may be varied depending on the position of the antenna of theother communication equipment. In such a case, a form which can receivea signal at high directivity from the antenna of the other communicationequipment as destination can be selected.

The gain check section 73 checks the gain of the antenna 50, based on acondition whether an S/N ratio of the signal received by the antenna 50is in the allowable range or not, and other conditions. In this case, itis desired that the S/N ratio be high. Therefore, if the ratio is acertain value or more, it is determined that the gain is good.

The impedance check section 74 checks the impedance matching propertybetween the antenna 50 and the communication circuit 61 based on acondition where a ratio of the level of the signal received by theantenna 50 to the level of the signal reflected from the communicationcircuit 61 is in the allowable range, or not, and other conditions.Specifically, if a ratio in level of the received signal by the antenna50 to the signal reflected from the communication circuit 61 is acertain value or more, it is determined that the impedance matchingproperty is good.

Preferably, until it is determined that all of the directivity, thegain, and the impedance matching property are good, the designing of theform of the antenna is repeatedly performed, in the form designingsection 53, and the driver 51 is adjusted again by the form designcontroller 54. When it is eventually determined that all of thedirectivity, the gain, and the input impedance matching property aregood, information (data) relating to the form is stored in the memory55.

The memory 55 stores an optimum form of the antenna 50 independently forthe case where the antenna 50 is used for reception (stand-by condition)and for the case where the antenna 50 is used for transmission. Thus, inaccordance with a switching signal for transmission/reception of theantenna 50, adjustment can be performed for changing the stored contentstaken out of the memory 55 to the form designing section 53.

Alternatively, an antenna form in which the directivity is low in thestand-by condition is first adopted, and then in a stage where thereception of a radio wave signal starts, an antenna form suitable forreceiving the radio wave signal is determined. In this way, optimizationof the antenna form may be dynamically performed.

According to this embodiment, optimum forms of various types of antennasshown in the first to eighth embodiments can be dynamically determinedand realized in accordance with the environments in which the antenna 50is used and the kind of equipment in which the antenna is incorporated.

TENTH EMBODIMENT

FIG. 32 is a block diagram showing another embodiment of the apparatusprovided with the antenna of the present invention.

The apparatus of this embodiment includes, in addition to theconfiguration of the ninth embodiment, a plurality of probes forchecking the directivity 75 a, 75 b, and 75 c which are disposed indifferent positions. FIG. 32 shows an example in which the three probes75 a to 75 b are disposed, but the number of probes may be four or more,or only two.

The operations or the functions of a form designing section 53, a formdesign controller 54, and a memory 55 in this embodiment are the same asthe operations or the functions of the form designing section 53, theform design controller 54, and the memory 55 in the ninth embodiment.

Also in this embodiment, the gain and the impedance matching propertyare checked as described in the ninth embodiment. Hereinafter a methodof checking the directivity which is characterized in this embodimentwill be described.

First, a procedure for adjusting the form in the case where the antenna50 is used as a transmitting antenna is described. In this embodiment,when a signal for transmission (generally, a signal standardized fortest) is sent from the communication circuit 61 to the antenna 50, andthe signal is transmitted from the antenna 50 to the external, signalswith different intensities depending on the disposed positions are inputinto a level detector 71 by means of the respective probes 75 a to 75 c.

In the directivity check section 72, it is determined whether thedirectivity of the transmitting function of the antenna 50 is in theallowable range or not, based on the level of the high frequency signal.Specifically, in the case where the level of the received signal isvaried depending on the respective probes 75 a to 75 c, if a differencein level of the received signals in the respective positions is in acertain range, it is determined that the directivity is in the allowablerange. If the difference is not in the certain range, it is determinedthat the directivity is not in the allowable range. In this way, thedirectivity of the antenna 50 in transmission is checked. There may be acase where it is desired that the directivity be as low as possible, anda case where it is desired that the directivity be as high as possible.For this reason, the range used for checking the directivity can bevaried depending on the type and application of the equipment in whichthe antenna is used, or the purpose of reception or transmission.

In the level detector 71, both of a level of the signal transmitted fromthe communication circuit 61 to the antenna 50 and a level of a signalreceived by the respective probes 75 a to 75 c are detected, so that thesignal transmitted from the communication circuit to the antenna 50 andthe reflected wave from the antenna can be additionally used for thecheck of the directivity.

Next, in the case where the antenna 50 is used as a receiving antenna,the probes 75 a to 75 c are not used. Similarly to the ninth embodiment,by using the level of a high frequency signal received by the antenna50, the directivity in reception of the antenna 50 can be checked. It isunderstood that the signal received by the probes 75 a to 75 c can beused as reference.

In this embodiment, in addition to the effects in the ninth embodiment,the directivity of the antenna 50 in transmission can be checked basedon the levels of the signal actually received by the probes 75 a to 75c, so that it is possible to optimally adjust the directivity of theantenna 50 in transmission.

ELEVENTH EMBODIMENT

FIG. 33 is a block diagram showing still another embodiment of theapparatus provided with the antenna of the present invention.

Also in this embodiment, the operations or the functions of a formdesigning section 53, a form design controller 54, and the memory 55 arethe same as the operations or the functions of the form designingsection 53, the form design controller 54, and the memory 55 in theninth embodiment.

As shown in FIG. 33, the apparatus of this embodiment utilizes anexternal communication circuit 62. That is, a signal from thecommunication circuit 61 is transmitted through the antenna 50, and thetransmitted signal is received by an antenna of external equipment. Asignal transmitted from the external communication circuit 62 inresponse to the transmitted signal is received by the antenna 50, andutilized for the adjustment of the form of the antenna 50.

The communication circuit 62 of the external equipment is a circuit fortransmitting information such as a time signal, or weather forecastingwhich is transmitted by making a call, for example. Depending on theapplication of the antenna 50, special external equipment for testhaving a communication circuit 62 can be prepared.

In this embodiment, the adjustment of the form of the antenna 50 can besimultaneously performed for both of the transmission and receptionpurposes. When the antenna 50 is used for transmission, the directivity,the gain, and the impedance matching property are checked by theprocedure described in the ninth embodiment, that is, without using anyexternal communication circuit. Only when the antenna 50 is used forreception, the external communication circuit 62 can be utilized. Alsoin this embodiment, similarly to the tenth embodiment, probes 75 a to 75c can be disposed for checking the directivity.

A directivity check section 72 determines whether the directivity of theantenna 50 in transmission and in reception is in the allowable range ornot, based on the level of the high frequency signal. Specifically, inthe case where the level of the signal received by the antenna 50 isvaried depending on the direction of the antenna 50, if a difference inlevel of the received signals in the respective directions is in acertain range, it is determined that the directivity in transmission andreception is in the allowable range. If the difference is not in thecertain range, it is determined that the directivity is not in theallowable range. Accordingly, the directivity in transmission andreception of the antenna 50 can be checked. Also in this case, there maybe a case where it is desired that the directivity be as low aspossible, and a case where it is desired that the directivity be as highas possible. Therefore, the range for checking the directivity is varieddepending on the type, the application, and the like of the equipment inwhich the antenna is used.

A gain check section 73 checks the gain of the antenna 50, based on thecondition where the S/N ratio of the signal received by the antenna 50is in the allowable range, or not, a ratio of the level of the signaltransmitted from the communication circuit 61 to the level of the signalthereafter received by the antenna 50, or other conditions. In thiscase, it is desired that the S/N ratio and the ratio of the level of thereceived signal to the level of the transmitted signal be as high aspossible. Thus, if the ratios are certain values or more, it isdetermined that the gain is good.

In addition, the impedance check section 74 checks the impedancematching property in transmission of the antenna 50, based on the levelof the signal reflected from the antenna 50 in transmission. Theimpedance matching property between the antenna 50 and the communicationcircuit 61 is checked, based on the level of the signal reflected fromthe communication circuit 61 after being received by the antenna 50.

Preferably, until it is determined that all of the directivity, thegain, and the impedance matching property are good, the designing of theform of the antenna is repeatedly performed in the form designingsection 53. By the form design controller 54 and the driver 51, the formof the antenna 51 is dynamically changed. It is eventually determinedthat all of the directivity, the gain, and the input impedance matchingproperty of the antenna 50 are good, information (data) relating to theform is stored in the memory 55.

TWELFTH EMBODIMENT

FIG. 34 is a block diagram showing still another embodiment of theapparatus provided with the antenna of the present invention.

Also in this embodiment, the operations or the functions of a formdesigning section 53, a form design controller 54, and a memory 55 arethe same as the operations or the functions of the form designcontroller 54 and the memory 55 in the ninth embodiment.

As shown in FIG. 34, the apparatus of this embodiment includes, insteadof the level detector 71 in the eleventh embodiment, a data analyzer 76.In this embodiment, it is assumed that an external communication circuit62 is utilized. After a signal from a communication circuit 61 istransmitted through an antenna 50, the signal is received by an antennaof external equipment. A signal transmitted from the externalcommunication circuit 62 in response to the signal transmitted from theantenna 50 is received by the antenna 50, and the received signal isutilized for adjusting the form of the antenna 50.

The communication circuit 62 of the external equipment in thisembodiment is a circuit for, when a certain test signal is received,outputting a digital signal in response to the test signal. As thecommunication circuit 62 of the external equipment, for example, acircuit for transmitting information such as a time signal, or weatherforecasting transmitted by making a call can be utilized.

In the eleventh embodiment, the form of the antenna 50 is adjusted inaccordance with the levels of the transmitted and received signals. Inthis embodiment, by comparing the data contents of the transmitted andreceived signals, it is determined whether the directivity, the gain,and the impedance matching property are in optimum ranges, or not. Otherfunctions are the same as those in the eleventh embodiment.

Also in this embodiment, similarly to the tenth embodiment, probes 75 ato 75 c can be disposed for checking the directivity.

THIRTEENTH EMBODIMENT

FIG. 35 is a block diagram showing still another embodiment of theapparatus provided with the antenna of the present invention.

The apparatus of this embodiment includes a form mechanism producingsection 56, instead of the driver 51 in the ninth embodiment. Also inthis case, the operations or the functions of a form designing section53, a form design controller 54, and a memory 55 are the same as theoperations or the functions of the form designing section 53, the formdesign controller 54, and the memory 55 in the ninth embodiment.

In this embodiment, by way of the same procedure as that in the eleventhembodiment, the form of an antenna 50 is judged, based on thedirectivity, the gain, the impedance matching property, and the like inrespective cases where the antenna 50 functions as an antenna fortransmission/reception, and an appropriate antenna form can bedetermined. In this embodiment, the form of the antenna cannot bedynamically changed during the use of the antenna. The form of theantenna is determined in a process step for producing an apparatus inwhich the antenna is incorporated.

Also in this case, similarly to the tenth embodiment, probes 75 a to 75c can be disposed for checking the directivity.

[Antenna Module]

In the above-described respective embodiments of the apparatus providedwith the antenna, the driver 51, the form design controller 54, and thelike as shown in FIG. 29 are disposed in various apparatuses such asterminal devices. A component in which a circuit for determining anantenna form (a control circuit for an antenna) is integrated with anantenna can be produced as an antenna module, and marketed.

FIG. 36 shows an antenna module in which the antenna of the presentinvention is integrated with a circuit for controlling the form of theantenna. In the antenna module, the antenna 50 of the present inventionis fixed on a package 80 of an integrated circuit chip. A circuit systemformed in the integrated circuit chip includes antenna control circuitssuch as the driver 51, the form designing section 53, the form designcontroller 54, the memory 55, the level detector 71, the directivitycheck section 72, the gain check section 73, the impedance check sectionshown in FIG. 29, and preferably includes the communication circuit 61.

Such an antenna module is used by being incorporated in an apparatus 90such as a portable terminal (including a cellar phone) shown in FIG. 36.An appropriate form of the antenna is varied depending on the apparatus90 on which the antenna module is mounted, and the use environments ofthe apparatus 90. According to the antenna module of the presentinvention, the form of the antenna is automatically changed to be anoptimum form depending on the use conditions of the portable terminal.

FIG. 37(a) schematically shows the directivity of the antenna 50 in astand-by mode of the portable terminal in FIG. 36. In the stand-by mode,the form of the antenna 50 is set so as to exhibit a wide directivity.In a mode for searching a destination for communication, a form with astrong directivity is given to the antenna 50, and the form issequentially changed. Thus, as shown in FIG. 37(b), the direction inwhich the antenna 50 has the strong directivity is changed. In theabove-described search mode, when the direction of the source of theratio waves generated from the other terminal is found, as shown in FIG.37(c), the form in which the directivity is the strongest in thedirection of the source is given to the antenna 50, and thetransmission/reception of the radio waves is efficiently performed.

FOURTEENTH EMBODIMENT

FIG. 38 is a perspective view showing an example of a communicationsystem in which the antenna of the present invention is used. FIG. 38exemplarily shows a communication system utilizing millimeter waves. Asshown in the figure, base stations are disposed on tips of a largenumber of line optical fibers branched from a trunk line optical fiber(Trunk Line O-Fiber). In addition, wireless communication net is formedfrom the respective base stations to the respective homes (or offices)for performing the communication by using millimeter waves. In wirelessterminals (or mobile stations) in respective homes or offices, thesupply of various media from the base station to the devices in therespective homes or offices, the internet communication, thecommunication between mobile stations, and the like can be performed.That is, the millimeter waves are easily subjected to electronic jammingby a material body, because the millimeter waves have a wavelength whichis closer to that of light. Therefore, transmission and reception ofdata by way of optical communication via optical fiber net to the basestation, and conversion is performed between an optical signal and anelectric signal in the base station. Between the home or office and thebase station, wireless access can be performed by utilizing millimeterwaves.

The antenna of the present invention is suitably used for transmissionand reception when the above-described wireless access is performed. Inpart of the system, between a base station directly connected to a trunkline optical fiber and a portable information terminal or a terminal inan office, wireless access can be performed via the antenna of thepresent invention.

FIG. 39 is a block diagram schematically showing a configuration of acommunication system between the base station shown in FIG. 38 and awireless terminal in each home or office. The communication system shownin the figure includes a number of base stations 101 mutually connectedby an optical fiber net (network) 100, and wireless terminals 102 formutually performing communication via the respective base stations 101.Each of the base stations 101 includes an antenna device 111 forreceiving and transmitting radio waves, a receiving amplifier 112 havingfunctions such as a function of amplifying a radio wave signal receivedby the antenna device 111, a transmission amplifier 113 for transmittingan amplified high frequency signal to the antenna device 111, a wirelesstransmitter/receiver 114 connected to the receiving amplifier 112 andthe transmission amplifier 113, a controller 115 for controlling theoperations of the respective devices, and a wire connecting section 116for connecting a signal between the base station 101 and the opticalfiber net 100. The wireless terminal 102 includes an antenna device 121for performing the reception and transmission of radio waves, areceiving amplifier 122 having functions such as a function ofamplifying a radio wave signal received by the antenna device 121, atransmission amplifier 123 for transmitting an amplified high frequencysignal to the antenna device 121, and a controller 125 for controllingthe operations of the respective devices.

FIG. 40 is a block circuit diagram showing an inner configuration of thebase station 101 in more detail. As shown in the figure, the antennadevice 111 is constituted by an antenna 11 a, and an antenna switch 111b for performing the switching between the transmission and thereception of the antenna 111 a. The receiving amplifier 112 isconstituted by two sets of a filter 131 and a low noise amplifier (LNA)132 which are disposed in series. In the wireless transmitter/receiver114, a mixer 134 for generating a high frequency signal by mixingoutputs of a local amplifier and a high frequency oscillator isdisposed. In the transmission amplifier 113, a driver amplifier 135, afilter 136, a middle amplifier 137, and a main amplifier 138 aredisposed. The wire connecting section 116 is constituted by a base bandsignal processor 117 for processing a sound signal, an interface 118,and an exchange controller 119 connected to the optical fiber net(network) 100. Although not shown in the figure, a signal converter forperforming conversion between an optical signal to an electric signal isdisposed in the interface 118.

The antenna of the present invention is used as the antenna 111 a, andfunctions as one slot in a slot antenna, for example.

Industrial Applicability

According to the present invention, an array of small conductor elementseach of which cannot independently function as an antenna is utilized,so as to provide an antenna in which a current pattern or a magneticcurrent pattern can be changed in a wide variety of ways.

1. Antenna comprising: an array of a plurality of conductor elementswhich are mutually separated, and each of which does not independentlyfunction as an antenna; coupling means for electro-magnetically couplingat least two conductor elements selected from the plurality of conductorelements, thereby causing the plurality of coupled conductor elements tofunction as one antenna element; and a dielectric layer for supportingthe plurality of conductor elements, wherein the coupling means includesconducting means for electrically connecting the plurality of selectedconductor elements, the conducting means includes a group of conductorpieces overlapping at least two adjacent conductor elements, theconductor piece is disposed so as to electrically connect the selectedconductor elements, and the antenna further comprises a dielectric filminterposed between the respective conductor elements and the respectiveconductor pieces.
 2. (Cancelled)
 3. The antenna of claim 1, wherein thearray of the conductor elements includes a matrix portion in which theplurality of conductor elements are arranged in a matrix of rows andcolumns.
 4. The antenna of claim 3, wherein the matrix portion of thearray is constituted by conductor elements having substantially the sameshape.
 5. The antenna of claim 3, wherein the matrix portion of thearray is constituted by conductor elements having substantially the samesize.
 6. The antenna of claim 3, wherein each of the plurality ofconductor elements has a size smaller than a wavelength of radio wave tobe transmitted and/or received.
 7. (Cancelled)
 8. (Cancelled)
 9. Theantenna of claim 1, wherein the conducting means includes a plurality ofswitching elements for switching electrically conducting/non-conductingconditions between two conductor elements.
 10. The antenna of claim 9,wherein the plurality of switching elements are arranged in a matrix ofrows and columns.
 11. The antenna of claim 10, further comprising awiring layer for connecting a circuit for driving the plurality ofswitching elements to the plurality of switching elements.
 12. Theantenna of claim 9, wherein the switching elements are transistors. 13.The antenna of claim 9, wherein the switching element includes aconductor piece which is movably supported, and an actuator for movingthe conductor element, and the actuator can reciprocate the conductorpiece between a first position in which a plurality of adjacentconductor elements are electrically connected by the conductor piece anda second position in which a plurality of adjacent conductor elementsare not electrically connected.
 14. The antenna of claim 1, wherein thedielectric layer has a first main face on which the array of conductorelements is disposed, and a second main face opposite to the first mainface, and a grounding conductor is formed on the side of the second mainface.
 15. Antenna comprising: an array of a plurality of conductorelements which are mutually separated, and each of which does notindependently function as an antenna; coupling means forelectro-magnetically coupling at least two conductor elements selectedfrom the plurality of conductor elements, thereby causing the pluralityof coupled conductor elements to function as one antenna element; and adielectric layer for supporting the plurality of conductor elements,wherein the coupling means includes conducting means for electricallyconnecting the plurality of selected conductor elements, wherein part ofa plurality of conductor elements selected from the plurality ofconductor elements function as a grounding conductor.
 16. The antenna ofclaim 1, wherein the dielectric layer, the conductor elements, and theconducting means are laminated.
 17. The antenna of claim 16, wherein theconducting means is provided in a movable manner, and the antennafurther comprises a moving mechanism for moving the conducting meansbetween a conducting position in which the at least two conductorelements are made to mutually and effectively conduct, and anon-conducting position other than the conducting position.
 18. Antennacomprising: an array of a plurality of conductor elements which aremutually separated, and each of which does not independently function asan antenna; and coupling means for electro-magnetically coupling atleast two conductor elements selected from the plurality of conductorelements, thereby causing the plurality of coupled conductor elements tofunction as one antenna element, wherein the coupling means includes aconductor layer, and a plurality of dielectric elements disposed betweenthe conductor layer and each of the conductor elements, and the selectedconductor elements are more strongly capacitive-coupled to the conductorlayer than the conductor elements which are not selected.
 19. Theantenna of claim 18, wherein the array of the conductor elementsincludes a matrix portion in which the plurality of conductor elementsare arranged in a matrix of rows and columns.
 20. The antenna of claim19, wherein the matrix portion of the array is constituted by conductorelements having substantially the same shape.
 21. The antenna of claim19, wherein the matrix portion of the array is constituted by conductorelements having substantially the same size.
 22. The antenna of claim19, wherein each of the plurality of conductor elements has a sizesmaller than a wavelength of radio wave to be transmitted and/orreceived.
 23. The antenna of claim 18, wherein the dielectric elementspositioned between the selected conductor elements and the conductorlayer are thinner than the dielectric elements positioned between theconductor elements which are not selected and the conductor layer. 24.The antenna of claim 18, wherein a specific inductive capacity of thedielectric elements positioned between the selected conductor elementsand the conductor layer is larger than a specific inductive capacity ofthe dielectric elements positioned between the conductor elements whichare not selected and the conductor layer.
 25. The antenna of claim 18,further comprising an actuator for moving the conductor elements so asto change a distance between each of the conductor elements and thedielectric layer.
 26. The antenna of claim 18, wherein the dielectricelements and the conductor elements are layered a plurality of times.27. An antenna module comprising: the antenna of claim 9; and a drivingcircuit for generating a signal for driving the plurality of switchingelements.
 28. An apparatus comprising: the antenna of claim 9; a drivingcircuit for generating a signal for driving the plurality of switchingelements; and control means for controlling the operation of the drivingcircuit, based on a signal received and/or transmitted by the antenna.29. An apparatus comprising: an antenna including: an array of aplurality of conductor elements which are mutually separated, and eachof which does not independently function as an antenna; coupling meansfor electro-magnetically coupling at least two conductor elementsselected from the plurality of conductor elements, thereby causing theplurality of coupled conductor elements to function as one antennaelement; and a dielectric layer for supporting the plurality ofconductor elements, the coupling means including conducting means forelectrically connecting the plurality of selected conductor elements,the conducting means including a plurality of switching elements forswitching electrically conducting/non-conducting conditions between twoconductor elements; a driving circuit for generating a signal fordriving the plurality of switching elements; control means forcontrolling the operation of the driving circuit, based on a signalreceived and/or transmitted by the antenna; and evaluating means forevaluating directivity, gain, and/or impedance of the antenna, based onthe signal, wherein conductor elements to be electrically connected aredynamically selected from the plurality of conductor elements, based onthe evaluated result.
 30. The apparatus of claim 29, wherein theevaluating means evaluates the directivity, gain, and/or impedance ofthe antenna for each of a plurality of combinations of conductorelements which are electrically and mutually connected by the switchingelements.
 31. The apparatus of claim 30, further comprising: a memoryfor storing the evaluated results for the plurality of combinations ofthe conductor elements; and a form designing section for selectingconductor elements to be electrically and mutually connected by theswitching elements and for controlling the operation of the drivingcircuit, based on the evaluated results stored in the memory.
 32. Asystem comprising a plurality of apparatuses of claim 31, whereincommunications are performed between the plurality of apparatuses byradio waves via antennas of the respective apparatuses, and connectionpatterns of the plurality of conductor elements are dynamically changedfor defining forms of the antennas of the respective apparatuses.